Aerodynamics is a significant factor in vehicle design, including automobiles. Automotive aerodynamics is the study of the aerodynamics of road vehicles. The main goals of the study are reducing drag and wind noise, minimizing noise emission, and preventing undesired lift forces and other causes of aerodynamic instability at high speeds. Additionally, the study of aerodynamics may also be used to achieve downforce in high-performance vehicles in order to improve vehicle traction and cornering abilities. The study is typically used to shape vehicle bodywork and add-on devices for achieving a desired compromise among the above characteristics for specific vehicle use.
A spoiler is an automotive aerodynamic device intended to “spoil” unfavorable air movement across a body of a vehicle in motion, usually described as turbulence or drag. Spoilers can be fitted at the front and/or at the rear of the vehicle body. Spoilers on the front of a vehicle are often called air dams.
When the vehicle is in motion, in addition to directing air flow, such front air dams also reduce the amount of air flowing underneath the vehicle which generally reduces aerodynamic lift and drag. Additionally, when the vehicle is in motion, the flow of air at the rear of the vehicle becomes turbulent and a low-pressure zone is created, increasing drag and instability. Adding a spoiler at the rear of the vehicle body can help to delay airflow separation from the body and a higher pressure zone created in front of the spoiler can help reduce lift on the vehicle body by creating downforce. In such instances, a rear spoiler can increase high speed stability of the vehicle due to the reduced rear lift. In other instances, a rear spoiler can be used to streamline the airflow to reduce aerodynamic drag of the vehicle body.